Daemon: \dā′ mon\ From the Greek daimon, meaning divine power, derived from the daemons of Greek mythology, which were supernatural beings that ranked between gods and mortals and possessing special knowledge and power. A Daemon originated in computer terms as “a background agent which worked tirelessly to perform system chores.”
Some examples of these chores include print spooling, email processing, automated backup utilities and the like. Key to a daemon’s existence is their respective completeness and autonomy – a typical daemon does relatively few things but will do them exceptionally well without failing.
The word daemon was first used in a computer context at the pioneering Project MAC (which later became the MIT Laboratory for Computer Science) using the IBM 7094 in 1963. This usage was inspired by Maxwell’s daemon of physics and thermodynamics, which was an imaginary agent that helped sort molecules of different speeds and worked tirelessly in the background. The term was then used to describe background processes which worked tirelessly to perform system chores. The first computer daemon was a program that automatically made tape backups. After the term was adopted for computer use, it was rationalized as an acronym for Disk And Execution MONitor.